1. Field of the Invention
This invention relates generally to devices for transporting patients consisting of emergency cot devices with collapsible and retractable wheel carriage structure, and especially to automatic wheel carriage retraction mechanism for such cots.
2. Description of the Prior Art
A common problem with known type emergency cots having collapsible wheel carriage structure is that while such carriage structure will drop upon release of an appropriate latch mechanism by an attendant supporting the cot and patient thereon, generally the only way to retract and collapse said wheel carriage structure is to lower the patient and supporting cot against the connecting struts of the wheel carriage with the latch mechanism held in the release position. Thus, effectively the weight of the patient with the latch mechanism held in release position will effect the collapse of the lower side of the cot frame work against the upper portion of the wheel carriage. This manner of collapsing is undesirable because the patient's head generally is put into an ambulance first and when the cot and patient are lowered to collapse the support structural wheel carriage, it places the patient's head quite close to the ambulance's exhaust. Normally, the ambulance engine is kept running, especially in winter when it is desired to keep the engine and interior warm, and thus the patient is exposed to the toxic fumes of carbon monoxide, etc. from the exhaust.
Another problem with known type devices for collapsing emergency cot wheel carriage structure is that they are not automatic, or even semi-automatic , in operation.
Another problem with known type devices is that they are unduly complicated and require frequent maintenance. Furthermore, the component parts are expensive and often times difficult to obtain when repairs are necessary.
Known prior art patents which may be pertinent to this invention are as follows: U.S. Pat. Nos. 2,958,873 Nov. 8, 1960 2,977,168 Mar. 28, 1961 3,245,366 April 12, 1966 3,644,944 Feb. 29, 1972 3,805,712 April 23, 1974
None of these known prior art devices offers the new and unique features of the invention disclosed herein.